Journal article
Quasilinear Analysis in the Source Region of Jovian Hectometric Emission Associated With Upward Electron Beams
Journal of geophysical research. Space physics, Vol.130(2), e2024JA033241
02/2025
DOI: 10.1029/2024JA033241
Abstract
Intense upward electron beams were measured by the Juno JADE instrument in the northern hemisphere, low‐latitude auroral zone source region. In this study we report on how these electron beams interact with plasma near and within the Jovian hectometric (HOM) emission (1 MHz 5 MHz) source region. Within the source region large upward loss cones are observed in the northern polar region at radial distances of 2Rj, magnetic latitude of . Intense, narrow electron beams ( 3 keV) are then observed, but within one second wave‐particle scattering is observed, filling the loss cone to energies 50 keV. These energies persist for several seconds before fading, leaving an empty loss cone again. The loss cone provides a free‐energy source for HOM emission resulting from the cyclotron maser instability. We use quasilinear analysis to examine the generation of HOM and the dynamics of wave‐particle interaction of the electron beams with HOM, and the generation via Landau interaction of whistler mode emission. The dynamic spectrum of the HOM emission generated by the loss‐cone electrons as well as that of the low‐frequency whistler‐mode waves generated by the up‐going electron beam can be constructed by quasilinear theory, which compare well with observation. The saturated state of the energetic electron velocity distribution function constructed via quasilinear theory also compare reasonably with observation.
NASA's Juno space probe orbiting the planet Jupiter measured energetic electrons streaming out from the northern polar region of the planet. These electrons were seen to travel in an environment permeated by high‐frequency radio emission called the Jovian hectometric emission. By employing a mathematical model known as the quasilinear plasma kinetic theory the essential characteristics of the electrons and the electromagnetic wave spectra measured by the Juno space probe are theoretically replicated. This exercise helps scientists understand the nature of physical processes taking place in the space environment surrounding the planet Jupiter.
Upward electron beams detected in hectometric (HOM) source region excite low‐frequency waves One‐sided loss‐cone electron distribution excites extraordinary mode via cyclotron maser instability, which leads to HOM emission The Observed wave spectra and particle characteristics can be modeled by employing quasilinear wave‐particle analysis
Details
- Title: Subtitle
- Quasilinear Analysis in the Source Region of Jovian Hectometric Emission Associated With Upward Electron Beams
- Creators
- P. H. Yoon - University of Maryland, College ParkJ. D. Menietti - University of IowaF. Allegrini - Southwest Research InstituteW. S. Kurth - University of IowaG. B. Hospodarsky - University of IowaT. F. Averkamp - University of IowaJ. B. Faden - Department of Physics and Astronomy University of Iowa Iowa City IA USAJ. E. Connerney - Goddard Space Flight CenterS. J. Bolton - Southwest Research Institute
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.130(2), e2024JA033241
- Publisher
- AMER GEOPHYSICAL UNION
- DOI
- 10.1029/2024JA033241
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Grant note
- Planetary Science Division: 80NSSC23K0662 NASA: 2203321, DOE DE-SC0022963 NSF: Z6536201 NSF/DOE Partnership in Basic Plasma Science and Engineering: 699041X NASA New Frontiers ProgramNASA New Frontiers Program for JunoRoy J. Carver Charitable Trust
The authors wish to thank J. Chrisinger for help with some of figures. P. H. Y. was supported by NASA Grant 80NSSC23K0662, NSF Grant 2203321, and the Department of Energy (DOE DE-SC0022963) through the NSF/DOE Partnership in Basic Plasma Science and Engineering. JDM acknowledges support from subcontract Z6536201 to the University of Maryland. Research conducted at the University of Iowa was supported by NASA New Frontiers Program through Contract 699041X with Southwest Research Institute. F. A. was funded by NASA New Frontiers Program for Juno. We acknowledge the use of the Space Physics Data Repository at the University of Iowa supported by the Roy J. Carver Charitable Trust. L. Granroth established the zenodo data archive site.
- Language
- English
- Date published
- 02/2025
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984786281902771
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